PURPOSE: To accelerate the activation of the molecules of water and to improve the taste of the water by mounting an electromechanical vibration converter to the tank for building feed water filled with water and supplying low-frequency signal currents of musical tones, etc., to this electromechanical vibration converter.

CONSTITUTION: The electromechanical vibration converter 5 is mounted to the tank 3 for building feed water filled with the water and the low-frequency signal currents of the musical tones, etc., are supplied to this electromechanical vibration converter 5. Namely, the integral assembly of a yoke 9, a magnet 10 and a top plate 11 is vibrated relative to the coil 15 by the magnetic interference effect of the coil 15 and the magnet 10. The tank 3 for feed water mounted with this converter 5 is vibrated in this way and the water filled therein is vibrated as well. Consequently, the activation of the water is accelerated and the taste of the water is improved.